Organic light-emitting diode (OLED) display technology has become the next generation display technology with high competitiveness and a broad development prospect because of processing a series of advantages, such as all solid state structure, high brightness, all viewing angle display, fast response, flexible display etc.
In the field of large-size organic light-emitting display, for example, a method of using white light and a color filter is used to display and a top emission mode is adopted to obtain a large opening rate and a low power consumption. As for a large-size display device of top emission mode, a transparent cathode layer on the light-exit side of the display device is, for example, a planar film layer covering the whole display region of the display device; in order to increase the transmittance rate, the transparent cathode layer is designed to be thin, and the transparent cathode layer which is relatively thin and covers a large region is easy to produce a large voltage difference between the center portion and the peripheral portion of the cathode layer, which affects the performance and life of the display device to a large extent.
For example, an auxiliary electrode is directly arranged on the transparent cathode layer to reduce the large voltage difference between the center portion and the peripheral portion. One solution is forming an auxiliary electrode directly on the transparent cathode layer; because the transparent cathode layer is covered with a sealing layer and the sealing layer is an integrated inorganic insulating layer, it is difficult to ensure a good sealing effect after forming the sealing layer on the auxiliary electrode and the transparent cathode layer. Another solution is forming an auxiliary electrode on a packaging cover substrate, and then the packaging cover substrate provided with the auxiliary electrode is aligned with and jointed with a lower substrate provided with the transparent cathode layer; in order to prevent the display effect in the display region from being affected by the auxiliary electrode, the auxiliary electrode is generally arranged in regions respectively between adjacent pixel units of the display device, which increases the difficulty of the aligning and jointing the packaging cover substrate with the lower substrate and reduces the production yield of the display panel of the display device.